MetService currently provides a year-round road weather programme to the Transport Agency, comprising road weather observations, forecasts and meteorological briefings. During winter, this service expands to include road surface temperature forecasting that determines the impacts of colder weather and the likelihood of freezing conditions and ice formation over the State Highway network.

The six-month data acquisition trial follows a pilot sensor-assessment process, and aims to expand road weather observation assets by evaluating the meteorological integrity and potential utility of a range of very precise vehicle-mounted sensors for monitoring road weather conditions across the network.

The sensors will be mounted on field vehicles operated by MetService, Fulton Hogan and Downer. As the host vehicles traverse the road network, they will transmit real-time data continuously to provide observations of road and air temperature, rain, snow, slush, water film height, ice content, humidity and dew point temperature. Some of the sensors are capable of taking measurements up to 100 times per second. Data can be visualised on smartphones connected to the sensors by Bluetooth and transmitted on cellular networks for subsequent analysis.

The data collected will deliver key insights for improving road weather forecasting and road safety in locations for which there is currently no weather information available.

MetService Business Development Manager Peter Fisher says this science-based innovation will help enhance road weather modelling systems and help MetService inform roading contractors how to optimise their application of the de-icing agent Calcium Magnesium Acetate (CMA). CMA, a low corrosion environmental alternative to road salt, is used in both granular and liquid forms to prevent snow and ice from bonding to the road surface.

The aim of the trial is to enable MetService, the Transport Agency and roading contractors to serve the future needs of transport operators and the travelling public by identifying treacherous areas in the road network. It will assist forecasters to pre-warn contractors and road users of challenging driving conditions and the potential for road closures and travel disruption during severe weather events.

“The Transport Agency, Fulton Hogan and Downer will have access to a wide range of previously unavailable data to assist with planning and operational activities so that roads can be kept as safe as possible for the travelling public,” says Mr Fisher.

“Drivers of the sensor host vehicles have immediate access to data to inform them of dangerous driving conditions, and fleet operators will have better quality, more timely information for fleet management.

In early August, Transport Agency Chief Executive Fergus Gammie joined MetService Chairman Anthony Howard and Chief Executive Peter Lennox at MetService headquarters in Wellington for a live demonstration of mobile data acquisition from a sensor mounted on a MetService vehicle.

“The concept of using vehicles in the field as mobile weather stations gathering accurate observations represents an opportunity to enhance MetService’s road surface observation network along our highways, bridges and near vital infrastructure,” add Fisher. Data from mobile sensors will complement information from MetService’s existing road weather station network, which covers over 40 state highway trouble spots including the Leith Saddle near Dunedin and the Desert Road.

“This investment reflects the commitment of the Transport Agency, Fulton Hogan, Downer and MetService to collaborate in delivering innovations that benefit the safety of all road users,” says Mr Fisher.